And what about all those diesel generators? How many of them are capable of running on vegetable oil rather than diesel oil? I regularly walk past a building in London that reeks because of the diesel fuel tanks in the basement. You have to wonder about the safety of storing large amounts of petroleum oil in the centers of major cities when vegetable oil is safer, and more carbon-friendly.
This is something I know about, as I home-brew fuel for my vehicles, and I operate a datacenter with backup power. ;) The issue with straight vegetable oil is that it must be pre-heated to >55°C to efficiently run in a Diesel engine without risk of injector or injector pump clogging. This is not exactly efficient for fail-over power generation as you would either need to build dual-tank and heating systems (still storing SOME petro-Diesel AND losing X% of your power generation facility to heating your fuel in the process... a LOT of electricity as most backup gensets have a LOT of fuel around to heat up... looking outside my office window I see two tanks, one 19000 liters, the other 30,000 liters in capacity.) Or you would need to mix that SVO with petroleum Diesel, to thin it enough to run risk free... negating your desire to rid yourself of petrochemical risk. This is moot in exceptionally warm climates or exceptionally cloud-free areas as passive solar could be used to store SVO at high temps. VO-based fuels are more likely to gel at lower temps than petro-fuels. Ask me how I know! Finally, vegetable oil has long term storage issues of the organic sort, where it can become contaminated with algae, bacteria, etc. BioDiesel, that is vegetable oil that has been chemically stripped of glycerines through transesterfication is a better suggestion to replace petro-Diesel in generators. It has cold weather and storage issues too, but generally performs better than SVO. --chuck